Styrene → Benzene, ethenyl-, polymer with 1,3-butadiene

Participants

Reaction Steps

A one gallon reactor containing 2,000 g. of purified cyclohexane was readied for polymerization of monomer as in Example I. Into the closed reactor was charged 8.86 m moles of sec-butyllithium and 132.9 of styrene and the reactor held at 60° C. for 20 minutes. The Mn was 15,000 for the resulting polystyrene blocks. At this point, 132.9 g. of butadiene were added and the whole mixture held at 60° C. for 75 minutes to form diblock arms of 50/50 wt-% styrene/butadiene and having average Mn of 30,000. There was then added either 17.72 m moles (coupling agent/RLi=2), 26.58 m moles (coupling agent/RLi=3), 35.44 m moles (coupling agent/RLi=4), or 53.16 m moles (coupling agent/RLi=6), of the desired linking agent and the temperature held at 30° C. to complete the linking reaction. After termination and separation of the polymeric product the results shown in Table I were obtained for unlinked diblock (DB), linked triblock (TB) and starblock.

Provenance & Evidence